The invention relates to an apparatus for deep drawing to a bowl which is open at one side from a blank of deep-drawable plastics material comprising deep drawing tools which are movable relative to each other, and co-operating jaws.
Apparatuses of that kind are known. In use of such apparatuses, one open bowl after another is deep drawn in a cyclic procedure from material in web form, removed from the mould and passed on to further processing stations.
However the known deep drawing apparatuses suffer inter alia from two major disadvantages. The first disadvantage is that the material in web form must be stopped for a prolonged period of time for the deep drawing operation because it is not possible for the period of time for completely heating through the deep-drawable plastics material to be less than a minimum time. It is only after the deep-drawable material has been completely heated therethrough that the deep drawing operation can be carried out. That means that the output of such a machine, that is to say the number of finished products per unit of time, is unavoidably subject to an upper limit.
The second disadvantage is that the material in web form is always necessary along a frame-like strip which extends around the deep-drawn bowl, on the one hand, for holding purposes and thus to permit the deep drawing operation to be carried out, but on the other hand, after the finished product has been made, it is generally a nuisance or superfluous and must then be cut off. Admittedly, in modern deep drawing apparatuses, the operating procedure involved has already changed over to stamping out the deep-drawn bowl and leaving the frame-like strip on the web of material and then rolling up the latter and possibly even re-melting it in order to use the material. That operation of stamping out the product from the web of material, rolling up the remaining material and possibly again melting it etc however involve additional and therefore expensive steps in the process.